Hydraulic motor and valve assembly



Oct. 28, 1952 c. E. DEARD ORFF ETAL 2,615,423

HYDRAULIC MOTOR AND VALVE ASSEMBLY Filed Feb. 2, 1948 v s Sheets-Sheet 1 9; 2g .95 26' A 9 AZ? /7 I n o- 1L 0 482 f i. 387 49 82.

INVENTORS AND ALVIN A.MDDOCK CLINTON E. DEARDORFF a3 BY W l ATTORNE.

Patented Oct. 28, 1952 HYDRAULIC MOTOR AND VALVE' ASSEMBLY CIinton EJ DeardorE, San Fernando, andi'Alvin A..

Meddock, North .-Hollywood;. Califi, assignors to" Bendix AviationCorporation, South Bend, Ind., acorporation of Delaware:

Application February 2, 1948, Serial No. 5,798

7 Claims.

This invention relates'to a control'devicefor utilizing the energy of hydraulic pressure fluid to produce controlled movement of a member to be actuated. More specifically, the invention relates to the hydraulic control of implements used foregoing desirable operating characteristics,.

with a simple, inexpensive and reliable structure. Other more specific objects and features of the invention will become apparent from the description to follow.

Briefly, the invention. comprises a double-act.-

ing hydraulic cylinder motor and control valve:

assembly in which,.accordingto1the way in. which the handle of the valve is manipulatedthe motor can be moved in either direction, either rapidly or slowly, and stopped inanyportion. of its travel under the full control of the operator, r;can be started in either direction by theoperator andv automatically stopped when-it reaches a prese lected position or the end of its stroke.

Referring to the drawing:

Fig. l. is a plan view. of a hydraulic motor'and valve assembly in accordance with the invention;

Fig. 2 is a front elevation of the assembly;

Fig. 31s a right end elevation of theassembly; 1

Fig. 4 is a vertical section taken: in the plane IV-IV of Fig. 2;

Fig. 5 is a horizontal section takenin the. plane V-V of Fig. 2;

Fig. 6 is a detail section taken inthe same plane as Fig. 5, but showing a. method of. blocking one of the passages; and

Figs. '7, S, and 9 are schematic diagrams illustrating the operation of the system.

Referring first to Figs. 1, 2, and 3, the complete assembly therein depicted comprises a motor cylinder unit l5 and a valve unit 16; the two units, being detachably securedtogether by cap, screws.

The motorcylinder unit l5 contains a piston 18' (Fig; 5) to which is connected a conventional pistonrod i9 which-extends through one end-2t or the cylinder and is sealedwith respect thereto by a conventional seal 2|. Exteriorlof the end wall 20, thepiston rod 19 (Figs. 1 and-'2) issecured to'a clevi-s 22' bymeans of which his connected to whatever device is to be controlled by the assembly. There is connectedto the clevis 22 'for reciprocation therewith; apis'ton rod member consisting of a b'entro-d 23 having a straight portion 23w extending parallel to the piston rod l9, which straight po'rtioncarries a pair'of longitudinal adjustable collars-'i'and-'26'-for-automatic restoration of thecontrolvalveto neutral position, as will be described later.

The cylinder 25 ofthemotor cylinder-unit i5 has fluid passages '21 and 28 which'extendfrom opposite ends of-the cylinder 2'5 and terminate in an exterior face 29 of the motor'cylinderunit, which face seats againsta" corresponding face '30 on'the'valveunit l5. Amotor"port"3l in'the'va'lve' unit. is juxtaposed to the cylinder port 2! and is sealed with respect theretoiby a sealingring 32'. A motor port 33in the valve unit It is juxtaposed: to the cylinder passage wand is'seal'ed with re spect thereto bya seal 34. In addition to 'the'passage 2 8; communication with'theri'ght en-d' ofthe cylinder 25 is provided for by an. external aux iliary' port 36' (Fig. 1). leading to the exterior of themotor cylinderunit, which port is'normall'y' plugged by a plugi Thevalve unit [6' has a longitudinal bore 37 constituting a valve cylinder in which a control member consisting of a valve piston .38, isreciprocable. The main portion. of this valve piston 38 is hollow,- providing.anintern-al passage 38-1 and has fourexternall'ands 382;. 383, 384 andtllii which seal with the valve cylinder 31. Pressed. into opposite ends; of the hollow piston 38" are a.

pair. of endmembers 3'86 and 387'. The. end member 386 extends. through and seals with. a valve cylinder end closure member lll "and: cooperates with a centering. spring mechanism. positioned within an endcapill on the valveunit [5f This.

When the valve piston 38 is in neutral position, as shown in Fig. 5, the external flange 43l of the thrust element 43 rests against a shoulder I6! constituted by the left end of the valve unit 16, and the flange 44l rest-s against the outer end of the cap 4|. The thrust element 43 has an internal flange 432 which bears against a shoulder 338a on the end member 386 so that leftward movement of the valve piston 38 must result in compression of the spring 42. Likewise the thrust element 44 has an inwardly extending flange 442 which bears against a split ring 433 on the end member 386, preventing movement of the valve piston 38 to the right Without compression o-f the spring 42.

The valve piston extension 381 extends through and seals with an end closure member 46 at the right end of the valve cylinder, and has a transverse hole 388 therein for receiving an actuating pin 48, the latter extendingfrom a lever 49 and being retained in the hole 388 by a cotter pin 50 and Washer The valve cylinder 31 (Fig. 5) is intersected by the motor ports 3| and 33 which extend thereinto horizontally. The valve cylinder is also intersected by a pressure port 52 and an exhaust port 53 which extend thereinto from the underside.

. A normally plugged port 54 i juxtaposed to the cylinder port 33. Another permanently plugged port 55 cooperates with the land 383 to by-pass fluid direct from the pressure port 52 to the exhaust port 53 when the valve is in neutral posi tion.

The hydraulic circuits will be readily apparent from inspection of Figs. '7, 8, and 9. Fig. 7 shows the arrangement when an auxiliary motor 60 is to be operated in synchronism with the motor [5. Under this condition the cylinder passage 28 is blocked by insertion of a plug Bl (Fig. 6) in the recess which contains the sealing ring 34, and the plug 35 (Fig. 1) is removed, and the port 36 is connected by a duct 62 (Fig. '7) to one end of the auxiliary motor 60, the other end of this cylinder being connected by a duct 63 to the port 54 of the valve. Since the port 54 and the motor port 33 (Fig. 5) are intercommunioated, fluid is supplied directly from the port 54 to the right end of the auxiliary motor cylinder 60 instead of to the right end of the motor cylinder 25, and fluid is supplied from the left end of the auxiliary cylinder 68 to the right end of the motor cylinder 25. Fluid connection between the left end of the motor cylinder 25 and the valve unit remains unchanged.

As shown in Fig. '7, the valve is in neutral position, in which pressure fluid supplied by a pump 65 to the pressure port 52 is by-passed through the blind port 55 past the piston land 383 to the exhaust port 53 from which it flows back to a reservoir 66.

Referring now to Fig. 8, the valve piston is shown moved to the left a short distance sufficient to carry the land 383 past the blind port 55, thereby cutting oif by-pass of pressure fluid from the pressure port 52 to the exhaust port 53. At the same time, the piston land 382 permits throttled flow of pressure fluid into the motor port 3[ and the left end of the jack cylinder 25. At the same time, the motor port 33 connected with the right end of the motor cylinder 25 is uncovered by the piston land 3B5, permitting flow of fluid into the right end 3H of the valve cylinder and thence through a passage 387a in the right piston extension 381 into the exhaust passage 3! within the piston 33, which exhaust passage is constantly communicated by a piston port 389 with the main exhaust port 53. At small openings of the valve, as shown in Fig. 8, the pressure drop past the land 382 into the motor port 31 and past the land 385 into the valve cylinder end 31! is large as compared to the pressure drop through the passage 381a, so that the pressure developed in the cylinder end 31] does not exert suflicient force against the right end face 38a of the piston 38 to overcome the restoring force of the centering spring 42 (Fig. 5). Therefore, if the manual force holding the valve in slightly open position, as shown in Fig. 8, is removed, the centering spring 42 will automatically restore the valve to neutral position. This operation is the same if the valve is moved in the other direction out of neutral, the pressure force against the left end 312 of the valve piston produced by the pressure drop through the passage 381?) in the left piston extension being insuflicient to overcome the restoring spring.

However, if the valve is moved into wide open position, as shown in Fig. 9, the pressure drop past the land 385 becomes relatively small as compared to the pressure drop in the passage 381a, so that the pressure in the right end 37! of the valve cylinder is suflicient to overcome the force of the centering spring 42 and maintain the valve in open position even though the manual force that opened the valve is removed. The valve then remains in open position until it is automatically restored to neutral by a mechanism to be described later.

When the motor piston is to be moved to the left, the valve handle 49 is swung to the right, out of the neutral position shown in Fig. 7. This applies pressure fluid from the pump 65, through the ports 52 and 8G, and the passage 11, and the port 8|, to the cylinder port 33. At the same time fluid from the left end of the cylinder 15 is exhausted through the duct 21 and the port 3! into the left end 312 of the valve cylinder, and thence through the restricted passage 38% into the piston passage 38! and thence through the exhaust port 389 in the piston, and the exhaust port 53 in the valve cylinder back to the reservoir 66. As in the operation previously described, if the handle 55 is moved only far enough to crack the valve, then the pressure fluid is delivered at a slow rate to the right end of the motor cylinder l5, and. the rate of flow of the exhaust fluid from the cylinder through the restricted passage 38112 is insuflicient to build up enough pressure in the left end 312 of the valve cylinder to move the valve piston against the force of its centering spring. However, if the lever 49 is swung farther to more fully open the valve, then the rate of flow through the restricted passage 3311) develops a sufllcient pressure drop which, when applied to the left end 38b of the valve piston holds it in right end position until the motor piston has completed its stroke, and flow of exhaust fluid through the passage 38117 ceases. Thereupon the centering spring becomes elfective to restore the valve to neutral position.

The particular valve construction shown in Fig. 5 is relatively inexpensive, since the valve cylinder 31 has no internal annular ports requiring special machining operations. The necessity of the usual annular ports or recesses is avoided by balancing each of the ports with an opposite blind port. As an example, the port 31 has a balancing blind port 31a which is produced in a single machining operation with the port 3|. Similarly the ports 52 and 53 have coiresponding blind ports. In some positions or the valve piston 38,

theland-S'BZ' completely covers the riortM-andits cooperating blind} port 31 a: and'hence thisland 382*is provided with "a circumferential groove 3820 which functions to equalize the pressures inthe ports 3 i-and 31 d at all times. Similarlya circumferential" groove 385a in the land 385-inte'rconnects the ports 33 and 54 th equalize the pres-' sures therein.-

It is usuallydesirable in systems of the type to which thisinvention relates to provide'areliet valve at some point in the'system to preventthe development of excessive pressures. In accord.-v ance with the invention, therelief'valve is economically incorporated in the valve unit; Thus as shown in Fig. there is'provided imme; diately above theexhaust port Et a-balancing port 53a which communicates with a reliefvalve chamber it which is formed in the valve unitifi and opens into the 'iace tii thereof. The valve chamber it is closed-by a closure plate H containing a port 22,- the inner endot which con-- stitutes a seat for a ball valve lit-which is urged against the seat by a helical compression spring i l. The closure plate H i sealed-with respect to the face 29' of the motor cylinder unit by a sealing ring '85. The port ilt-in the closure plate it communicates with a port lt in the jackcylinder unit l5 which port (Fig. 5) communicates with a passage "I"! in the motor cylinder unit which terminates in a pair of ports is and Win the face 29. These ports normally intercommunicate a pressure port 89 in the-valve unit, which is in constant communication with the main pressure port 52, and a port 8|, which is in constant communication with the'annular space defined within the valve cylinder between the piston lands 38d and 385, and through which pressure fluid is supplied to themotor port 33 connected with the right end of the motorcyb inder 25. 7 It will be apparent therefore that the ball valve 73 is at all times exposed to the-full pressure in the pressure port 52'and is at all times efiective to relieve excessive pressures by exhaust ing fluid through the valve chamber ill, the port 53a, and the valve cylinder, into exhaustport 53;

As previously mentioned, the valve-pistons tension 337: isconnected by a pin 48 to an actuating lever is. Referringto Figs. 1-, 2, and 3; this actuating lever 49 is bifurcate at its lower end and. straddles a stationary screw. 82 which is screwed into thezmotor unit'lfi. The head 82a of, the screwlimits movement of the lower end of the lever 49 outwardly, and thelever is yieldably urged against thehead Ma by a compression spring 83. This spring 83 normally retains the lever is in the position. shown in Figs. 1 and 3,

in which the upper end. 49a.of.-the lever this in the pathjof the stop collars and 2601a the rod 23a. Under these conditionsrrby suitably positioning the collars 24 and Non the rod 23, they can be caused to contact thelever 49 and restore it to neutral position in response-t0 movement of: the motor piston rod. it into predetermined positions.

The lever 69 can be actuated by a handle Eli;

s; adapted-to .begra'sped at its. outerend by the-- 6' operator. Cooperating with the section S ll-b of 'the handle is a stationary IuIcrumLmember- Q-Zhaving a face 93- juxtaposed to the handle iit in all posi tions ofithe latter. A torsionspring see (Fig. 3) encircling-theportion of the straight part 95a; of the rod that is within the U-shaped partofthe lever 69urges the portion Hilbcfthehandle to'ward :thefulcrum member 92 21.13 all times, but with insufficient forceto-overcome the-helicalcompressionspring 83. i 9 1 There are many circumstances under whichit is desirable to cause the. motor'piston' rod" I9: to

move rapidly inzone direction or the other of its stroke and be stopped automatically at positions determined .by the settings of i the collars '24 and 2 6; Under these circumstances; theoperatorsimply' swing's the handle 90in direction-to rock the lever 49; without: compressing the spring 83, and- There are other-occasions in which it is desire.

able to efiect slowmovement of the piston rod 195 and stop it in a selected position. This operation can best be performed by rocking the handle 90:

against'the fulcrum 92 with sufficientforce to overcome the spring 83 (Fig; 3).and rockthelever 49 and the valve piston rod 381 sufiiciently to carry the upper end 4900 ofthe lever out of the path of the collars 24 and 26 and into alignment with a pair of stop screws 94 and 95 on the member;92. These stop screws 94 and 95 are so'adjusted that when the lever end 49a is moved into contact therewith, the valve isopened only slightly as. shown in Fig. 8, so that the pressure drop in the passage 381a orjthepassage 381bLis insufiicient to. holdthe valve in operated position. Therefore, if, aftermoving the'lever as described' to carry the lever end 49a against one ofthe stop screws 94 M85, the operatorreleases the handle 90, itand the valvesare automatically restored to normal position by the ,valve-*centering spring: 42' (Fig; 5') and the lever restoring spring 900 (Fig; 3).

Occasion may arise when theoperator wishes to move thepiston rod 19 rapidly to a position be--. yond that corresponding to the settings of the collars 24 and 26.

previously described in which it is interrupted neither by the collars 24 or Zli nor the stop screws- 94 or 95. It is to be notedthat during this mode I of operation the pressure force exerted on the end 38a or 381) ofthe valve piston 38 by the pressure fluid can be readily overcome by the operator. Furthermore, if the operator fails to manually restore the valve to neutral position before the jack piston [8 reaches the end of its stroke, restoration of the ValVxpiSton to normal is automatically efiected by the centering spring 42, because when fluid ceases to flow from the motor cylinder there.

is no longer any'pressure drop through thepassage33'la or38lb.

Although for the purpose of explainingathe invention, a particular embodiment. thereof hasbeen-shown and described, obviousmodifications will-occur. to a person skilled in the-art, and we'donot desire'to be limite'd to the exact details shown" and-described.-

He can do this by rockin the handle 90 sufiicient to move the upper end 49a of. the lever into a path intermediate the two paths- 7 a We claim:

1. Hydraulic apparatus comprising: a motor cylinder unit defining a motor cylinder and having an exterior face and spaced motor ports in said face connected by passages in said unit to opposite ends of said motor cylinder; a valve unit having an exterior face seating against said cylinder face and having motor ports registering with said motor ports in said cylinder unit face; means for detachably securing said units to each other with their seating faces in engagement; said valve unit defining a valve cylinder intersected by said motor ports and also defining main pressure and exhaust .ports intersecting said valve cylinder; one of said jack ports in said valve unit extending through said valve cylinder and terminating in an auxiliary external port, and said motor cylinder unit having an auxiliary external port in the same end as said one motor port; said one motor port in one of said units having a counterbore extending into that unit from the face thereof, a resilient sealing ring in said counterbore for sealing between said faces about said one motor port, and a disc of thickness approximating the depth of said counterbore and diameter less than said counterbore and greater than said port positioned in said counterbore within said sealing rin for blocking said one motor port; whereby an auxiliary motor can be connected in series with said motor cylinder for actuation in synchronism therewith by connecting the auxiliary motor between said two auxiliary ports, and said motor can be directly connected to said valve unit by removing said disc and plugging said auxiliary port.

2. Hydraulic apparatus comprising: a motor cylinder unit defining a motor cylinderand having an exterior face and spaced motor ports in said face connected by passages in said unit to opposite ends of said jack cylinder; a valve unit having an exterior face seating against said cylinder face and having motor ports registering with said motor ports in said cylinder unit face; means for detachably securing said units to each other with their seating faces in engagement said valve unit defining a valve cylinder intersected by said motor ports and also defining main pressure and exhaust ports intersecting said valve cylinder; said valve unit having blind balancing ports-in said valve cylinder opposite said mentioned ports therein; a valve piston reciprocable in said valve cylinder and having a land juxtaposed to and closing off one of said ports in one position of said piston; said land having a circumferential groove therein for intercommunieating a port and its balancing port when the land is juxtaposed to such ports; said one port and its balancing port each consisting of a single cylindrical passage of smaller diameter than said valve cylinder, and both passages havin alined axes intersecting the axis of said valve cylinder, whereby the orifices of said passages at the valve cylinder are separated by portions of the valve cylinder wall; said land being rigid throughout and having a continuous cylindrical wall closely fitting said cylinder wall on each side of said groove, the groove being of substantially less width than thewidth of said orifices and constituting the sole free fluid connection between said one port and its balancing port when said land is interposed therebetween.

p3 Hydraulic apparatus comprising: a motor cylinder unit defining a motor cylinder and having an exterior face and spaced motor ports in said face connected by passages in said unit to opposite ends of said motor cylinder; a valve unit having an exterior face seating against said cylinder face and having motor ports registering with said jack ports in said cylinder unit face; means for detachably securing said units to each other with their seating faces in engagement; said valve unit defining a valve cylinder intersected by said motor ports and also defining main pressure and exhaust ports intersecting said valve cylinder; said valve unit having a second pressure port in its face communicating with said main pressure port; said motor cylinder unit having a pressure passage terminating in third and fourth ports in the face of the motor unit, the third port registering with said second port; a relief valve chamber in said valve unit, said chamber having an outlet passage to said main exhaust port and opening into the seating face of the valve unit in registration with said fourth port; a closure plate closing the opening of said chamber, said plate having an aperture defining a valve seat at its inner end; a valve for said seat; and spring means within said chamber urging said valve against said seat.

4. Apparatus according to claim 3 in which said valve unit has a shoulder in said chamber for supporting said closure plate, and fluid sealing means between said plate and the seating face of said cylinder unit.

5. Hydraulic apparatus comprising: a hydraulic motor; a valve cylinder and piston unit; said cylinder and piston unit defining a restricted exhaust passage extending through said piston from one end of said cylinder, said cylinder having a pressure port and motor ports intermediate the ends thereof, and said valve piston having lands for selectively and variably controlling fiow of fluid from said pressure port to said motor. and from said motor through said one cylinder end, and said restricted exhaust passage to exhaust, said piston lands, pressure port and motor po rts being so positioned that movement of the piston out of a neutral position away from said one end of the cylinder permits fluid flow through one motor port to said motor, and from said motor through the other motor port to said one cylinder end, and through said restricted passage to exhaust, whereby the pressure force of said piston due to the pressure drop across said restricted passage assists said piston movement.

6. Apparatus according to claim 5, in which said piston lands include a pair of spaced lands sealing with the cylinder wall and defining therewith an exhaust chamber, said piston has a passage extending therethrough communicating said exhaust chamber with said one end of said cylinder, and an exhaust port in the cylinder wall communicating with said exhaust chamber for discharge of said exhaust fluid therefrom.

7. Apparatus according to claim 6 in which said piston defines a pair of independent restricted passages therewithin separately communicating said exhaust chamber with opposite ends of said cylinder, said piston is movable in either direction for neutral position, and the lands, pressure port and motor ports are so positioned that movement of the piston out of neutral position away from the other end of the cylinder permits fluid flow through the other motor port to said motor, and from the motor through said one motor port to said other cylinder end, and through the restricted passage in the adjacent end of the piston to exhaust, whereby the pressure force on said piston due to the pressure drop in one of said restricted passages assists movement of said piston in each direction away from neutral position.

CLINTON E. DEARDORFF. 'ALVIN A. MEDDOCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 789,026 Huston May 2, 1905 799,236 Johnson Sept. 12, 1905 Number Number Name Date Brown June 16, 1942 Brown et a1 Feb. 16, 1943 Meredith Apr. 18, 1944 Temple June 24, 1947- Sedgwick July 1, 1947 Eaton July 29, 1947 Stephens Sept. 7, 1948 Watson Feb. 22, 1949 Hayden Apr. 25, 1950 FOREIGN PATENTS Country Date Great Britain Feb. 14, 1939 

